滑坡联动在滑坡及滑坡群中作用分析——以千将坪滑坡为例

受2003年7月13日千将坪滑坡的影响,位于其北东侧牵引区的千将坪东滑坡大范围出现了因拉张和剪切作用形成的裂隙。本文研究了因滑坡联动作用而形成的牵引区特征,对千将坪滑坡发生时在千将坪东滑坡体上所产生的裂隙形成作用方式进行了研究,并分析了千将坪滑坡体不同部位在滑坡滑动过程中的相互牵引与影响方式。通过研究分析,将滑坡滑动时的牵引方式简单分为以拉张卸荷为主和以边界剪切为主的两种模式,并以这两种牵引模式来分析白果树滑坡群中各个滑坡之间的相互制约关系,拟通过从滑坡联动作用阐述千将坪滑坡以东白果树滑坡群的整体稳定及局部失稳对滑坡群整体稳定性的影响。     

Experimental investigation of the earthquake response of a model of a marble classical column

Experimental results concerning the earthquake response of a marble model of a classical column are reported herein. The model was a 1: 3 scale replica of a column of the Parthenon on the Acropolis of Athens, made from the same material as the original. Several earthquake motions, scaled appropriately in order to cause significant rocking but no collapse of the column, were used as the excitation. The base motion was applied in plane (in one horizontal and the vertical direction) or in space (in two horizontal and the vertical direction), using the shaking table facility at the Laboratory for Earthquake Engineering of the National Technical University of Athens. It was found that the column might undergo large deformations during the shaking, which are not necessarily reflected by the residual displacements at the end of it. For planar excitations, significant out‐of‐plane displacements can happen, triggered by the inevitable imperfections of the specimen. It was also verified that the response is very sensitive, even to small changes of the geometry or the input motion parameters. For this reason, the experiments were not repeatable and ‘identical’ experiments produced different results. Copyright © 2002 John Wiley & Sons, Ltd.     

深水牵引流沉积的研究历程、现状与前景

深水牵引流沉积研究,是沉积学研究中一个较新的领域。在这个领域中,我国学者做出了应有的贡献,并且具有自己的特色和优势。目前研究的深水牵引流沉积,一是等深流沉积,二是内波、内潮汐沉积。等深流沉积研究开始于20世纪60年代,早期主要是对小规模的细粒薄层等深流沉积的研究,而现在已发展到对大规模等深流沉积体--等深岩丘的研究。内波内潮汐沉积研究始于20世纪90年代,也是从小规模内波、内潮汐沉积的鉴别开始,现在已达到研究深海大型沉积物波的阶段。今后等深流沉积研究的主攻方向,应是地层记录中的等深岩丘,并特别注意碎屑岩等深岩丘的发现和研究。内波、内潮汐沉积方面,最有矿产意义的当属由大型沉积物波构建的地质体。而首例地层记录中的大型沉积物波,已在塔里木盆地中部奥陶系中被鉴别出来,并具有含油气远景。从目前对内波、内潮汐的研究势头来看,我国很有希望在该领域继续保持国际领先地位。     

眼斑拟石首鱼的生化组成及预测模式

测定了养殖眼斑拟石首鱼肌肉及鱼体中的蛋白质、脂类、灰分和水分等生化组成。分析了肌肉蛋白质中17种常见氨基酸的含量。建立了以鱼体体重、体长、含水量与蛋白含量、脂肪含量、灰份、比能值的回归关系的预测模型。回归结果表明，眼斑拟石首鱼的鱼体组分与鱼体重、含水量间呈显著线性相关，而与全长则呈乘幂函数，基本呈立方关系，比能值与体重无相关性，其相关系数蛋白质＞水份＞灰分＞脂肪＞比能值。     

内潮汐和内波沉积研究现状与展望

根据国内外内潮汐、内波及其沉积的研究成果,概述了它们的研究进展,详细阐述了内潮汐、内波沉积特征和沉积类型,探讨了内潮汐、内波沉积研究的油气勘探意义。虽然内潮汐、内波沉积研究取得了较大进展,但仍存在着较多问题,如内潮汐、内波沉积的识别是该领域研究的最大难题。因此,在其未来研究上,应注意运用地震波识别、遥感等现代科技调查手段,进行多学科综合研究,尽快建立一套完善的识别标志,以促使其逐渐成为海洋沉积学中一个更为完善的研究领域。     

库水位升降作用下大型堆积体边坡变形破坏预测

库岸边坡的变形破坏及稳定性研究是目前国内外研究的热点之一。基于水电站库区一大型堆积体边坡,通过现场原位直剪试验获取岩土体的力学参数,利用岩土数值分析FLAC3D软件,考虑了堆积体与基岩基覆接触带介质的应变软化特性,对水库蓄水和下降过程中边坡的变形破坏特征进行了分析预测。结果表明,在库水升降作用下变形主要发生在堆积体内部;根据堆积体的变形特征可分为3个区：前缘牵引变形区,变形量最大;中间过渡区,变形量最小;后缘被牵引变形区,变形量介于前缘和中间之间。模拟过程中,在坡体的不同位置设置位移监测点,得到了蓄水和水位下降过程中各监测点的位移时程曲线,监测结果显示,水位下降时堆积体前缘易形成局部失稳。通过剪应变增量判断堆积体边坡在库水作用下可形成2个潜在的滑动破坏面     

Development of dynamic slip model for a shear crack

<正>The objective of this paper is to develop a dynamic slip model for a shear crack under constant stress drop.This crack problem is formulated by a traction boundary integral equation(BIE) in the frequency domain and then solved by the hyper-singular boundary element method as well as the regularization technique proposed in this paper.Based on the spectral integral form of the kernel function,the unbounded term can be isolated and extracted from the hyper-singular kernel function by using the method of subtracted and added back in wave number domain.Finally,based on the inverse transformation from the frequency domain to the time domain,the time histories of crack opening displacement under constant stress drop can be determined.Three rupture models(simultaneous rupture model,symmetric bilaterally-propagating model and unilaterally propagating model) with specified time histories of stress drop are considered in this paper.Even though these three models will cause the same final slip shapes because of the same constant stress drop,the associated slip time functions differ significantly from each other during the rupture process.     

眼斑拟石首鱼胚胎及仔鱼、稚鱼发育的初步观察

本文初步观察描述了眼斑拟石首鱼胚胎发育及仔鱼、稚鱼的形态特征。眼斑拟石首鱼的卵径平均为０．９５ｍｍ,大多数含１个油球,约＜１０×１０－２含２个油球,１ｃｍ３卵含量约１０００粒。受精卵在２３～２４．３℃约２６ｈ孵化出仔鱼。在２５℃条件下,前半个月仔鱼日增长约０．２ｍｍ,稚鱼期日增长约１．０ｍｍ,幼鱼期日增长约１．５ｍｍ。仔鱼鳍的发育顺序为尾鳍、臀鳍、背鳍和腹鳍,最后为胸鳍。     

Parametric investigation of the stability of classical columns under harmonic and earthquake excitations

The seismic response of free‐standing classical columns is analysed numerically through implementation of the distinct element method. Typical sections of two ancient temples are modelled and studied parametrically, in order to identify the main factors affecting the stability and to improve our understanding of the earthquake behaviour of such structures. The models were first subjected to harmonic base motions. The analysis showed that, for frequencies usually encountered in earthquake motions, intact multi‐drum free‐standing columns can withstand large amplitude harmonic excitations without collapse. The dynamic resistance decreases rapidly as the period of the harmonic excitation increases. Imperfections, such as initial tilt of the column or loss of contact area due to edge damage, also reduce the stability of the system significantly. The effects of such imperfections could be additive and the cumulative effect of many imperfections may render deteriorating abandoned monuments vulnerable to earthquakes. The response of more complete sections of the temple, such as two columns coupled with an architrave, did not deviate systematically from that of the single multi‐drum column or indeed of the equivalent single block. Therefore, a much simpler single block analysis can be used to size‐up the seismic threat to the monument. The model of the column of the Temple of Apollo at Bassae was also tested under recorded earthquake motions by scaling‐up the acceleration amplitude progressively until collapse of the column. It was found that the columns are particularly vulnerable to long‐period impulsive earthquake motions. A comparison of the instability thresholds associated with harmonic excitations and earthquake motions throws more light onto the dynamic response: it appears that around three cycles of monochromatic excitation at the predominant period of the expected earthquake motions lead to a gross prediction of the stability of a classical column during an earthquake. Copyright © 2000 John Wiley & Sons, Ltd.     

大连地区南北向剪切滑褶变形

大连地区经历了漫长而又特殊的地质构造演化过程，自中生代以来，全区处于活动大陆边缘环境，并遭受多期构造变形事件的影响，其中大规模南北向剪切滑褶变形为资产发现并确定，其为区内众多变形事件中规模最大、影响最广的一期构造事件，本文在详细的地质调查基础上，初步研究分析了研究区南北向剪切滑褶变形的构造-岩石组合特征及变形模式，并就变形动力学背景及变形时代进行了探讨。